Desensitization Still Achieved With Long-Term, Low-Dose Peanut OIT

The use of lower maintenance doses of oral immunotherapy (OIT) for prolonged periods can still result in complete desensitization in patients experiencing difficulties with peanut-OIT.

In a patient cohort of 11 patients aged 6 to 19 years with peanut allergy were given doses of peanut protein with the goal of achieving complete desensitization, allowing for unlimited peanut consumption. The objective post-therapy was to complete an oral food challenge of up to 3000 mg peanut protein.

The patients were given starting doses of 12.5 mg (range, 3–150 mg) of peanut protein, eventually reaching mean maximum dose of 1200 mg (range, 600–1500 mg) for a duration of an average of 5 months (range, 3–13 months).

“The doses were gradually increased on a monthly basis as patients were able to tolerate more peanut protein,” study author Arnon Elizur, MD, said in a statement. “Eleven patients, ranging from 6 to 19 years-old, were unable to reach the target maintenance dose and were placed on lower maintenance doses of peanut protein, as tolerated.”

Patients in the cohort were instructed to receive an in-hospital administered initial induction-desensitization phase to determine the maximally tolerated doses were determined. Following that determination, patients were instructed to consume the dose daily at home, with doses increased in monthly day-hospital care settings.

Of the 11 patients, 8 (73%) reached full compliance with the daily dose ingestion, with 3 patients occasionally halting treatment for longer than a week. In the long-term follow-up after 24 months (range, 6–68), the average skin-prick test (SPT) wheal size was 3.6 mm, reduced from 8.9 mm at baseline.

The oral food challenge of up to 3000-mg peanut protein was successfully completed by 10 of the 11 patients (91%). One of the patients with a maintenance dose of 600 mg experienced a reaction to 2100 mg peanut protein.

“A small portion of patients will not be able to reach the 3000-mg target maintenance dose,” Elizur, a member of the faculty in the department of pediatrics at Tel Aviv University’s Sackler School of Medicine, said. “However, this study shows that even lower doses, are not only protective against severe reactions in the case of accidental exposure to peanut but also can enable free peanut consumption long-term.”

There were only 4 subjective reactions reported. In total, 5 of the 11 patients (45%) experienced anaphylaxis reactions during at-home treatment, including a single patient that required the use of an epinephrine auto-injector (Epi-Pen).

Knowledge is limited in regard to the long-term therapeutic efficacy of lower maintenance doses, the authors noted, however, these data provide promise for larger cohort studies and future research.

The study data was presented at the 2018 American Academy of Allergy, Asthma, and Immunology (AAAAI)/World Allergy Organization (WAO) Joint Congress in Orlando, Florida.